Helical Acting Straight Snap Roll Flutes for Corn Header

ABSTRACT

A helical-acting snap roll for a harvesting header having straight flutes which are free of a formed twist. The snap roll includes elongated straight flutes that extend substantially the entire length of the snap roll but that are parallel misaligned with a central axis of rotation of the snap roll. A pair of opposing and counter-rotating snap rolls of the present invention chops and pulls crop stalks passing therebetween downward toward the ground while also creating a helical action such that the crop stalks are conveyed rearward.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of co-pending U.S.provisional application entitled “CORN HEADER (P0921)”, having Ser. No.61/375,196, filed Aug. 19, 2010; of co-pending U.S. provisionalapplication entitled “TILTING CROP STALK CHOPPER (P1177H)”, having Ser.No. 61/426,090, filed Dec. 22, 2010; of co-pending U.S. provisionalapplication entitled “PIVOTING GATHERING AUGER FOR CORN HEADER(P1171H)”, having Ser. No. 61/425,836, filed Dec. 22, 2010; ofco-pending U.S. provisional application entitled “CROP CAPTURING MEMBERFOR CORN HEADER WITH GATHERING AUGER (P1172H)”, having Ser. No.61/425,887, filed Dec. 22, 2010; of co-pending U.S. provisionalapplication entitled “GATHERING AUGER WITH INDEPENDENT SPEED (P1173H)”,having Ser. No. 61/425,907, filed Dec. 22, 2010; of co-pending U.S.provisional application entitled “COMBINATION DRIVEN AND IDLER SNAPROLLS FOR CORN HEADER (P1174H)”, having Ser. No. 61/425,920, filed Dec.22, 2010; of co-pending U.S. provisional application entitled “SPRINGLOADED SNAP ROLL FOR CORN HEADER (P1175H)”, having Ser. No. 61/425,935,filed Dec. 22, 2010; of co-pending U.S. provisional application entitled“HELICAL ACTING SNAP ROLL FLUTES FOR CORN HEADER (P1176H)”, having Ser.No. 61/426,072, filed Dec. 22, 2010; of co-pending U.S. provisionalapplication entitled “REMOVABLE CORN HEADER SNOUT (P1178H)”, having Ser.No. 61/426,119, filed Dec. 22, 2010; of co-pending U.S. provisionalapplication entitled “OFFSET SNAP ROLLS FOR CORN HEADER (P1179H)”,having Ser. No. 61/426,141, filed Dec. 22, 2010; of co-pending U.S.provisional application entitled “DUAL IDLER ROLLS FOR CORN HEADER(P1180H)”, having Ser. No. 61/426,167, filed Dec. 22, 2010; ofco-pending U.S. provisional application entitled “SNAP ROLLS WITHHELICAL FLUTES FOR CORN HEADER (P1181H)”, having Ser. No. 61/426,193,filed Dec. 22, 2010; of co-pending U.S. provisional application entitled“SMOOTH IDLER ROLL FOR CORN HEADER (P1182H)”, having Ser. No.61/426,213, filed Dec. 22, 2010; of co-pending U.S. provisionalapplication entitled “OFFSET STRIPPER PLATES FOR CORN HEADER (P1183H)”,having Ser. No. 61/426,234, filed Dec. 22, 2010; of co-pending U.S.provisional application entitled “METHOD FOR URGING CROP STALKS INTO AGATHERING AUGER FOR A CORN HEADER (P1184H)”, having Ser. No. 61/426,263,filed Dec. 22, 2010; of co-pending U.S. provisional application entitled“HELICAL ACTING STRAIGHT SNAP ROLL FLUTES FOR CORN HEADER (P1185H)”,having Ser. No. 61/426,277, filed Dec. 22, 2010; of co-pending U.S.provisional application entitled “TWISTED STALK CHOPPING FLUTES FOR CORNHEADER (P1190H)”, having Ser. No. 61/426,300, filed Dec. 22, 2010; ofco-pending U.S. provisional application entitled “CANTILEVERED GATHERINGAUGER FOR CORN HEADER (P1193H)”, having Ser. No. 61/425,804, filed Dec.22, 2010; which are all incorporated herein by reference in theirentirety.

TECHNICAL FIELD

This invention relates to cutting and gathering stalk crops such as cornwith a header coupled to an agricultural vehicle.

BACKGROUND

Agricultural harvesters such as combines are typically equipped with aharvesting header. Corn headers are specifically designed to pick cornand vary in size from two-row units to twelve-row units or more. As theharvester moves through the field, each row-unit passes between rows ofcorn. Corn header row units typically use gathering chains to covey cropmaterial and ears rearward toward a cross auger. A set of driven snaprolls, which rotate based on the speed of the harvester, grabs the cornstalks and forces them downward between stripper plates. The ears ofcorn are snapped free of the stalk and the cross auger passes the earsto the feeder housing of the harvester. If the snap rolls are operatedtoo fast or too slow, ears of corn may be lost or entire corn stalks maybe passed to the cross auger and feeder housing.

Known row units require two gathering chains and two tensioners whichare heavy, expensive and wear out easily. Furthermore, the gatheringchains create a complicated drive mechanism because the axes of thedrive sprockets driving the chains are at right angles to the axes ofthe snap rolls. Also, the gathering chains do not effectively convey alarge mass of crop in conditions when material other than ears of corn,such as stalks and leaves, are severed from the ground. What is neededis a simpler and more cost effective row unit that is capable ofconveying a large mass of crop.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this disclosure, illustrate various embodiments of the presentinvention. In the drawings:

FIG. 1 shows a perspective view of a corn header having a plurality ofrow units for an agricultural vehicle;

FIG. 2 shows a top view of the header of FIG. 1;

FIG. 3 shows a close-up view of a portion of the header of FIG. 1;

FIG. 4 shows a portion of the bottom of the header of FIG. 1;

FIG. 5 shows a close-up view of a portion of the bottom of the header ofFIG. 1;

FIG. 6 shows a perspective view of a frame which forms part of a liverow unit and part of an adjacent dead row unit;

FIGS. 7-9 is a top view of a pair of opposing snap rolls with straightflutes illustrating in sequence a point traveling from the leading endto the trailing ends of the snap rolls having a scissors action as thesnap rolls rotate; and

FIGS. 10-12 is a front view of the pair of snap rolls of FIGS. 7-9illustrating in sequence the point traveling from the leading end to thetrailing ends of the snap rolls having a scissors action as the snaprolls rotate.

DESCRIPTION OF EXAMPLE EMBODIMENTS

The present invention is susceptible of embodiment in many differentforms. While the drawings illustrate and the specification describescertain preferred embodiments of the invention, it is to be understoodthat such disclosure is by way of example only. There is no intent tolimit the principles of the present invention to the particulardisclosed embodiments. References hereinafter made to certaindirections, such as, for example, “left” and “right”, are made as viewedfrom the front looking rearward.

The exemplary header 100 selected for illustration in FIGS. 1-5 has across auger 110 with spiral flighting 112 for sweeping the ears of corntoward the center of the header 100. Large cross augers 110 may alsohave paddles 130, fingers 132 or some other means to facilitate thedelivery of the crop rearward to the feeder housing of a harvester. Theheader 110 has a plurality of forward-extending live row-units 120 and aplurality of forward-extending dead row units 124. The row units 120,124 and the cross auger 110 define a feeder plane therebetween whereuseable parts of stalk crops are conveyed rearward from the row units120, 124 to the cross auger 110.

Live row units 120 and dead row units 124 cooperate with one another.Live row units 120 have powered components, as described in greaterdetail below, whereas the dead row units 124 generally do not havepowered components. In one embodiment, as best shown in FIGS. 1 and 2,the header 110 has four live row units 120, three dead row units 124,plus one half of a dead row unit 130 on each end of the header 110. Therow units 120, 124 are arranged relative to one another so that the rowunits 120, 124 alternate relative to each other along the length of theheader 110. In other words, every other row unit is a live row unit 120with a dead row unit 124 adjacent to each live row unit 120. The rowunits 120, 124 are spaced relative to one another to correspond with thespacing of the crop to be harvested and to provide a path to receive thecrop therebetween. For example, a live row unit 120 may be placedbetween two dead row units 124 to cooperate therewith.

FIG. 6 illustrates a row assembly 138 having a frame 140, a back end 142and a forward end 144. Half of the frame 140 forms part of a live rowunit 120 and the other half forms part of a dead row unit 124.Therefore, one live row unit 120 includes two halves of two separate andadjacent frames 140. One dead row unit 124 includes two halves of twoseparate and adjacent frames. Each frame 140 includes a first portion146 and a second portion 148 which are spaced from one another andprotrude outwardly and forward from the back end 142. At the front andbetween adjacent row units 120, 124 is a crop entry 150 for receivingthe stalks of the crop. The first and second portions 146,148 receivestripper plates 154 which cooperate with one another to define the croppassage 156 between adjacent row units 120, 124. The stripper plates 154strip useable parts such as ears of corn from crop stalks that arereceived in the crop passage 156.

Each live row unit 120 of the present invention includes at least onefore-to-aft gathering auger 160, in place of the two gathering chainsand tensioners, for conveying the useable parts rearward to the crossauger 110. Each gathering auger 160 has a proximal end and a distal endand is preferably aligned substantially with a corresponding croppassage 156. However, the axis of rotation of the gathering auger 160may instead be misaligned with the crop passage 156 such that the cropstalks in the back of the crop passage may be urged more so toward thegathering auger 160 than the crop stalks are at the beginning of thecrop passage 156.

Preferably, each live row unit 120 includes a pair of counter-rotatingaugers 160. The dead row units 124, on the other hand, do not includegathering augers 160 or any gathering chains. Therefore, the complexityof the header 110 is reduced by utilizing gathering augers 160 on liverow units 120 instead of gathering chains and tensioners. Also, byutilizing dead row units 124 in combination with the live row units 120the overall complexity of the header 110 is substantially reducedbecause the dead row units 124 do not have gathering augers 160 orgathering chains and tensions and also because the drive means fordriving the gathering augers 160 is simpler than known drives used incombination with gathering chains.

The gathering augers 160 are preferably driven independently of the snaprolls. The gathering auger 160 may be driven by electrical, mechanicalor hydraulic means. Preferably, each gathering auger 160 is cantileveredfrom the frames 140 and rotationally driven from the forward most end ofits respective row unit 120 away from the cross auger 110 rather thanthe rear of the row unit 120 in close proximity to the cross auger 110so that the delivery or the distal end of the gathering auger 160 is notobstructed. This allows ears and stalks to be delivered to the crossauger 110 unimpeded by bearing supports, drive mechanisms or some othercrop impeding structure.

In one or more embodiments of the present invention, the proximal end ofone or more gathering augers 160 is coupled to the frame 140 of the rowunit 120 in a manner that permits the distal end of the gathering auger160 to move into and out of the feeder plane. In one embodiment, amechanism coupled to the proximal end of the gathering auger 160 allowsthe gathering auger 160 to rotate or pivot in a vertical plane between afirst position for processing crops when harvesting and a secondposition for maintenance purposes. Preferably, the distal end of thegathering auger when in the first position is higher in the verticalplane than when the distal end is in the second position.

Also, the gathering auger 160 preferably pivots partially about asubstantially horizontal rotational axis that extends substantiallytransversely between the row units 120. The gathering auger 160 may bepivoted such that its distal end is raised upward above the row unit 120to allow the gathering auger 160 to be repaired, replaced or performmaintenance without interference from the cross auger 110. Also, whenthe gathering auger 160 is pivoted upward out of the feeder plane othercomponents can be more easily accessed.

An arrangement of gears or wheels such as bevel gears 182, 184 may beused for transmission of the driving motion to the gathering auger 160from a driven shaft 166 within each live row unit 120 while alsoallowing the distal end of the gathering auger 160 to pivot upward aboutthe same axis of the shaft 166. Each shaft 166 preferably drives a pairof gathering augers 160 of a single live row unit 120 so that the pairof gathering augers are driven about the same axis about which they maypivot into and out of the feeder plane. When the gathering auger 160 ispivoted upward, fasteners may be removed from the auger 160 so that theouter flighting portion of the gathering auger 160 may slide rearward sothat it may be removed from an inner shaft and from cylindrical bearingsallowing the flighting portion to rotate about the inner shaft.

A mounting bracket 210 rotationally couples the gathering auger 160 toan outer side of the frame 140 of the row assembly 138, such as verticalmounting support 220, to secure the gathering auger 160 to the frame 140in an operational manner. The vertical mounting support 220 includesradial extending openings or arched slots 224 for receiving fasteners226 for securing the mounting bracket 210 to the frame 140. When thedistal end of the gathering auger 160 is pivoted upward, the distal endof the gathering auger 160 coupled to the mounting bracket 210 causesthe mounting bracket 210 to rotate in the slots 224 of the verticalmounting support 220. The length of the arched slots 224 dictate therange the gathering auger 160 can be pivoted between the first andsecond positions. The range of motion of the distal end of the gatheringauger 160 may be limited by the length or shape of the slots 224.

The pair of straight bevel gears 182, 184, in mesh are used to drive thegathering auger 160 while harvesting. The shaft 166 of the live row unit120 corresponds with the axis upon which one or more augers 160 pivot.The distal end of the gathering auger 160 is coupled to the bevel gear182 which is driven by the bevel gear 184 on shaft 166. The shaft 166may be chain driven by a hydraulic drive motor 178 with sprocket 180.Preferably, the drive motor 178 is sufficiently sized to drive all ofthe gathering augers 160. The drive motor 178 and sprocket 180 withchain 198 drives sprocket 188 and shaft 186 which extends in atransverse manner along the length of the header 100. There arepreferably numerous other sprockets 188 along the length of the shaft186. The number of sprockets 188 depends on the number of live row units120. Chains 190 extend from the sprockets 188 of the shaft 186 tosprockets 192 on shaft 166.

Because the augers 160 are driven by the drive motor 178, the speed ofthe augers 160 is independent of the speed of the cross auger 110. Thechain 190 driving the sprocket 192 which in turn drives the shaft 166with bevel gears 182. The speed of the augers 160 can be changedautomatically or manually in relation to the ground speed much likecurrent grain headers on harvesters that control reel speed. Moreover,the augers 160 can be driven independent of the snap rolls. The speed ofthe gathering augers 160 may be varied while either or both theharvester and the snap rolls are maintained at a constant speed.

In addition to the apparatuses described herein, the inventions includea method for harvesting crop with an attachment for an agriculturalvehicle that includes the gathering augers 160. The method includesoperating the gathering augers 160 at a first speed to gather cropstalks in the crop passages 156 and operating a snap roll for removinguseable parts from crop stalks at a second speed independently of thegathering augers 160. The method may also include one or more of thefollowing steps: varying the speed of the gathering augers 160 while thespeed of the snap rolls remain constant, increasing the speed of thegathering augers 160 while the speed of the snap rolls remain constant,decreasing the speed of the gathering augers 160 while the speed of thesnap rolls remain constant, varying the speed of the snap rolls whilethe speed of the gathering augers 160 remain constant, increasing thespeed of the snap rolls while the speed of the gathering augers 160remain constant, decreasing the speed of the snap rolls while the speedof the gathering augers 160 remain constant, and/or changing the speedof the gathering augers 160 relative the ground speed of the harvester.

To keep stalks captured and engaged by the gathering auger 160 anelongated member 196 such as a rod is positioned in close proximity tothe flighting of the gathering auger 160. Preferably, the elongatedmember 196 is substantially parallel aligned with the gathering auger160. However, in other embodiments, at least a portion of the elongatedmember 196 may be shaped or curved along its length or the distal end ofthe elongated member 196 may be closer in proximity to the distal end ofthe gathering auger 160. The elongated member 196 may be rigid,flexible, or semi-flexible to urge the stalks in the crop passage towardthe gathering auger 160. In one or more embodiments, the elongatedmember 196 is cantilevered off the forward end 144 of the frame 136 ofthe dead row unit 124 to urge the stalks in the crop passage 156 towardthe gathering auger 160 of the opposing live row unit 120. The dead rowunit may also include a second elongated member 196 extending towardanother gathering auger 160 of another live row unit. In an alternativeembodiment, the elongated member 196 may be a strap or be detachablycoupled or mounted to a row unit.

Underneath the stripper plates 154 of each frame 140 are one or moresnap rolls. At each crop passage 156 there is one driven snap roll 230on one side of the crop passage 156 and one or more undriven idler rolls232 opposing the snap roll 230 from the other side of the crop passage156. Angled bearing supports may be used to mount the snap rolls andidler rolls to the frames.

Because the idler rolls 232 are undriven, the powered snap roll 230 isoperated at different speeds relative to the idler rolls 232.Preferably, the powered snap roll 230 opposes a pair of idler rolls 232.On each side of a live row unit 120 there is a driven snap roll 230 andon each side of a dead row unit 124 there is at least one idler roll232. Preferably, each side of the dead row unit 124 includes two idlerrolls 232 for a total of four idler rolls 232 for each dead row unit124. Unpowered idler rolls 232 preferably have smooth outer peripherieswithout knives or bars and are lighter and less expensive which helps toconserve power that could instead be used to chop stalks with mowers asdescribed below.

Preferably, the powered snap rolls 230 include knives 234. If the idlerroll 232 where to be powered it could be powered at a slower speed thanan opposing snap roll 230. Also, the idler roll 232 could be adjustablerelative to the side of the frame 136 of a dead row unit 124 so that itcould be moved closer to the snap roll 230 for stalk chopping or movedaway when reduced stalk chopping is desired.

One or both ends of the idler roll 232 could also be spring loaded toallow it to move away if an obstruction is encountered in the croppassage 156. The angle bearing could incorporate a spring or a springcould be used at the opposite end to bias the idler roll toward the cropstalks and the opposing snap roll but then also allow an obstruction topass between the opposing idler and snap rolls by compressing thesprings.

The inventions also include a method for harvesting stalk crops with anattachment for an agricultural vehicle. The method includes pulling cropstalks in a crop passage with a snap roll against at least one stripperplate. The method also includes biasing the snap roll toward the cropstalks in the crop passage and allowing the snap roll to move laterallyin the event of an obstruction in the crop passage impacting the snaproll. The movement of the snap roll allows the obstruction to pass.

A single idler roll 232 is preferably offset from its opposing snap roll230 in that the snap roll 230 and idler roll 232 are at differentheights or different distances from the ground so that the corn plant isnot pulled straight down or in other words is pulled down at other thana perpendicular angle to the ground. If utilizing a pair of idler rolls232 to oppose the snap roll 230, upper and lower idler rolls 232 arepositioned so that the axis of rotation of the driven roll 230 isvertically between but horizontally offset from the axis of rotation ofeach idler roll 232. The axes of rotation of both idler rolls 232 arepreferably both parallel and vertically aligned with each other becausethe idler rolls 232 are at different distances from the ground relativeto each other.

One or more idler rolls 232 vertically offset from their opposing andcorresponding snap roll 230 helps to lean or urge the corn plant towardthe gathering auger 160 which is positioned on one side of a live rowunit 120. Also, in one or more embodiments, the stripper or deck plates154 may also be offset from one another relative to the ground to urgethe crop to the side of the crop passage 156 with the gathering auger160. Improved cutting action is achieved by running the knives 234, alsocommonly referred to as flutes or bars, of the powered snap rolls 230 inclose proximity to the one or more opposing idler rolls 232. A pair ofidler rolls 232 cooperating with one another to oppose a snap roll 230further increase the cutting and chopping ability by enhancing theengagement of the stalks in the knives 234 of the snap roll 230. Asshown in FIGS. 31-33 and 49, the header 100 may be equipped with one ormore straight helical-acting snap rolls 310. The snap roll 310 includesa plurality of straight knife or straight bar portions 320 arranged toextend outward from the roll 310 and relative to one another to achievethe same results that a formed helical knife would. Because the portions320 are straight relative all or at least most of their lengths they arefree of a formed twist and therefore easier to manufacture compared to atwisted helical knife. Some of the straight portions 320 are closer inproximity to the leading end of the snap roll 310 while others arecloser to the trailing end. But leading ends of the trailing straightportions 320 extend forward of or overlap trailing ends of the leadingstraight portions 320 creating a continuous cutting action. Therefore,the length of a leading straight portion 320 is partially parallelmisaligned with the length of a corresponding trailing straight portion320 on their respective side of the snap roll 310. Each of the straightportions 320 does not extend beyond its own flat member 346 or outersurface 350. The straight portions 320 of a pair of opposing andcounter-rotating snap rolls 320 cooperate with one another to chop cropstalks and create a helical action to convey crop stalks rearward.Preferably, each portion 320 includes a distal cutting or knife edgethat is elliptical rather than having an edge of constant radius.

The straight knife/bar portions 320 are mounted to flat members 346which are in turn preferably mounted with fasteners 348 to outer sidesor surfaces 350 of the body of the snap roll 310. Other than cones 362,the outer surfaces 350 of the snap roll 310 are preferably flat or atleast other than round for easy of manufacture. The straight portions320 are mounted at an angle rather than parallel aligned to therotational axis of the snap roll 310. In other words, the straightportions 320 are misaligned with the central axis of rotation of thesnap roll 310.

Knife portions 320 on one snap roll 310 should run in close proximity tothe knife portions 320 on a counter-rotating and opposing snap roll 310to achieve a scissors like action that continuously chops and cutsstalks. The knife portions 320 are preferably mounted so that the distaledges of the opposing knife portions are run point to point but mayinstead be run point to heel. Because the opposing snap rolls 310 arerotating in opposite directions the opposing knife portions 320 run inthe same direction downward between the opposing snap rolls 320. Whenthe knives of opposing snap rolls 310 are point to heel the knives areconsidered to be going in the same direction down between the opposingsnap rolls 310. When the knives of opposing rolls 310 are point to pointthe knives are considered to run to each other because the points ofopposing knife portions face one another.

In one or more embodiments, the header 100 includes opposing andcounter-rotating snap rolls 370, 372 having straight portions 374, 376,respectively, as shown in FIGS. 7-12. The straight portions 374, 376preferably extend along most or all of the length of the snap rolls 370,372 (excluding the pickup cones 378, 380) and therefore the snap rolls379, 372 are free of a formed twist. Each one of the straight portions374, 376 is mounted to a flat member 382 which is in turn preferablymounted with fasteners 384 to outer sides or surfaces of the body of thesnap rolls 370, 372. The outer sides are preferably flat or otherwiseother than round to facilitate receiving the flat members 382 and easeof manufacture. Each straight portion 374, 376 extends longitudinally onthe snap rolls 370, 372 but diagonally across a corresponding side ofits respective snap roll 370, 372. As the snap rolls 370, 372counter-rotate, distal edges of each of straight portion of snap roll370 extends outward to oppose distal edges of each correspondingstraight portion 376 of snap roll 372. The distal edges are preferablyat least partially elliptical in shape.

As best shown in the sequence of FIGS. 7-9 and again in FIGS. 10-12,when snap rolls 370, 372 are counter-rotating a portion of one straightportion 374 of snap roll 370 works along a portion of a correspondingstraight portion 376 of snap roll 372 to define a point for engagingcrop stalks between corresponding straight portions 374, 376. As snaprolls 370, 372 counter-rotate the point moves from leading ends of thesnap rolls 370, 372 toward trailing ends of the snap rolls 370, 372. Ascissors action is defined at the point as the point moves that createsa continuous cutting action. The corresponding straight portions 374,376 separate from one another following the point as the point movesfrom leading ends to trailing ends of the straight portions 374, 376.FIGS. 7 and 10 illustrate the point along corresponding straightportions 374, 376 at the leading ends of the snap rolls 370, 372. FIGS.8 and 11 illustrate the point along corresponding straight portions 374,376 in the middle of the opposing snap rolls 370, 372. FIGS. 9 and 12illustrate the point along corresponding straight portions 374, 376 atthe trailing ends of the opposing snap rolls 370, 372.

Still referring to FIGS. 7-12, each of the straight portions of snap 374roll 370 corresponds with a respective one of the straight portions 376of snap roll 372 during a single rotation of snap rolls 370, 372. Duringone revolution of the snap rolls 370, 372 the point runs substantiallythe entire lengths of the corresponding straight portions 374, 376.Corresponding straight portions 374, 376 are continuously displaced fromone another until working against one another again at their leadingedges during a subsequent rotation of the snap rolls 370, 372. Duringeach revolution of the snap rolls 370, 372, another straight portion ofeach snap roll 370, 372 correspond with each other to define anotherpoint that moves from leading ends to trailing ends of these othercorresponding straight portions 374, 376.

Straight portions 374, 376 are substantially straight relative at leastmost of their length, but because each straight portion 374, 376 extendsdiagonally, they are misaligned with a central axis of rotation of theirrespective snap roll 370, 372. A leading end of each straight portion374 extends toward an edge of a corresponding side of its respectivesnap roll and its trailing end extends toward another opposing edge ofthe same side. The straight portions 374 of snap roll 370 cooperate withstraight portions 376 of snap roll 372 to chop crop stalks passingtherebetween. Counter-rotation of snap rolls 370, 372 chops and pullscrop stalks passing therebetween downward toward the ground while alsocreating a helical action with straight portions 374, 376 such that thecrop stalks are conveyed rearward. The downward pulling, chopping andreward conveying are performed substantially simultaneously.

The foregoing has broadly outlined some of the more pertinent aspectsand features of the present invention. These should be construed to bemerely illustrative of some of the more prominent features andapplications of the invention. Other beneficial results can be obtainedby applying the disclosed information in a different manner or bymodifying the disclosed embodiments. Accordingly, other aspects and amore comprehensive understanding of the invention may be obtained byreferring to the detailed description of the exemplary embodiments takenin conjunction with the accompanying drawings, in addition to the scopeof the invention defined by the claims.

What is claimed is:
 1. A first snap roll in combination with a secondsnap roll for harvesting stalk crops wherein said first and second snaprolls comprise first and second pluralities of straight portions,respectively, each of said straight portions substantially straightrelative at least most of their length, said first and second snap rollsopposing one another and when counter rotating a portion of one of saidstraight portions of said first snap roll works along a portion of acorresponding one of said straight portions of said second snap roll todefine a point for engaging crop stalks between said correspondingstraight portions and as said first and second snap rolls counter rotatesaid point moves from leading ends of said first and second snap rollstoward trailing ends of said first and second snap rolls, saidcorresponding straight portions separating from one another followingsaid point as said point moves from leading ends to trailing ends ofsaid straight portions of said first and second snap rolls.
 2. The firstand second snap rolls of claim 1 wherein during one revolution of saidfirst and second snap rolls said point runs substantially the entirelengths of said corresponding straight portions.
 3. The first and secondsnap rolls of claim 1 wherein each of said straight portions of saidfirst snap roll corresponds with a respective one of said straightportions of said second snap roll during a single rotation of each ofsaid first and second snap rolls.
 4. The first and second snap rolls ofclaim 1 wherein said corresponding straight portions are continuouslydisplaced from one another until working against one another again atleading edges of said corresponding straight portions during asubsequent rotation of said first and second snap rolls.
 5. The firstand second snap rolls of claim 1 wherein another straight portion ofeach of said first and second snap rolls correspond with each other todefine another point wherein said other point moves from leading ends totrailing ends of said other straight portions of said first and secondstraight portions.
 6. The first and second snap rolls of claim 1 furthercomprising a continuous scissors action at said point as said pointmoves.
 7. The first and second snap rolls of claim 1 wherein said firstand second snap rolls each comprise an outer surface with said first andsecond plurality of straight portions extending from said respectiveouter surfaces, distal edges of each of said straight portions of saidfirst snap roll extending from said outer surface of said first snaproll such to oppose distal edges of each corresponding said secondplurality of straight portions.
 8. The first and second snap rolls ofclaim 1 wherein counter-rotation of said first and second snap rollschops and pulls crop stalks passing therebetween downward toward theground while also creating a helical action with said first and secondplurality of straight portions such that the crop stalks are conveyedrearward.
 9. The first and second snap rolls of claim 1 wherein an outersurface of each of said first and second snap rolls is other than round.10. The first and second snap rolls of claim 9 wherein said outersurfaces each comprise a plurality of sides, each said straight portionextending diagonally across a corresponding one of said sides.
 11. Thefirst and second snap rolls of claim 10 wherein each said side is flat.12. The first and second snap rolls of claim 1 wherein each saidstraight portion includes a distal edge that is at least partiallyelliptical in shape.
 13. The first and second snap rolls of claim 1wherein said first and second snap rolls are otherwise free of a twist.14. The first and second snap rolls of claim 1 wherein each of saidfirst and second snap rolls comprises an outer surface defined by aplurality of sides and wherein a leading end of one of said straightportions extends toward an edge of a corresponding one of said sides anda trailing end of said one straight portion extends toward anotheropposing edge of said corresponding one of said sides.
 15. The first andsecond snap rolls of claim 1 wherein said straight portions of saidfirst snap roll cooperate with said straight portions of said secondsnap roll to chop crop stalks passing between said first and second snaprolls.
 16. A first snap roll for a harvesting header comprising a firstplurality of outwardly and longitudinally extending straight portions,said straight portions substantially straight relative at least most oftheir length, and said straight portions misaligned with a central axisof rotation of said first snap roll.
 17. The first snap rolls of claim16 in combination with a second snap roll having a second plurality ofoutwardly and longitudinally extending straight portions whereincounter-rotation of said first and second snap rolls with said first andsecond plurality of straight portions pulls crop stalks passingtherebetween downward toward the ground while also chopping andconveying the crop stalks rearward.
 18. A method of harvesting stalkcrops, said method comprising the steps of: receiving crop stalksbetween opposing snap rolls; pulling the crop stalk downward to theground; striping useable parts from the crops stalks as a result of saiddownward pulling step; and conveying the crop stalks rearward whilepassing between said snap rolls.
 19. The method of claim 18 furthercomprising the step of chopping said crop stalks as said crop stalkspass between said snap rolls.
 20. The method of claim 19 wherein saiddownward pulling, said chopping, and said conveying steps are performedsubstantially simultaneously.
 21. The method of claim 18 wherein saiddownward pulling and said conveying steps are performed substantiallysimultaneously.